just a feweeks after being released from rehab, lindsay lohan says she's failed her latest drug test. could shbe heading back to jail? a new setback for the troubled star, "today," saturday, a new setback for the troubled star, "today," saturday, september 18th, 2010. captions paid for by nbc-universal television >>> good morning, everyone. welcome to "today" on a saturday morning. i'm lester holt. >> and i'm amy robach. we're all certainly glad to have you back in the seat this morning. >> i'm glad to be here. i went east a little bit. so i'm wide awake. >> that's good. >> it's good to be back. we've got a lot to tell you about this morning. for sarah palin the big question people have been asking, will she or won't she run for president? but when you go to iowa a couple years before the election, that starts the talk all over again. it was the important state of iowa, palin spoke at a major republican gathering last night. that only heightened speculation about a possible run in 12. we'll look at the possibilities in just a few minute >> all right. and then plenty of stormy weather,